The following relates to print platforms. It finds particular application to a print platform with at least two marking engines with different page per minute processing rates.
In conventional xerography, an electrostatic latent image is created on the surface of a photoconducting insulator and subsequently transferred to a final receiving substrate or medium. This typically involves the following. An electrostatic charge is deposited on the photoreceptor surface (e.g., by a corona discharge). The photoreceptor is exposed, which selectively dissipates the surface charge in the exposed regions and creates a latent image in the form of an electrostatic charge pattern. The image is developed by transferring electrostatically charged toner particles to the photoreceptor surface. The toner particles are then transferred to a receiving substrate or to one or more intermediate transfer elements and then to the receiving substrate. The transferred image is made permanent by various techniques, including pressure, heat, radiation, solvent, or some combination thereof.
With conventional multi-engine systems (xerographic or other) with at least one high speed marking engine (e.g., a high speed black and white marking engine) and at least one lower speed marking engine (e.g., a lower speed color marking engine) and a single print path, a print job may be distributed across the at least two marking engines. In many instances, the lower speed marking engine sends its output to a print buffer for suitable insertion into a media path at an appropriate place. This works well as long as the ratio of the page per minute rate of the lower speed marking engine to the higher speed marking engine is greater than the ratio of the number of pages processed by the lower speed marking engine to the number of pages processed by the higher speed marking engine. When this inequality is not satisfied, there may be skipped pitches in which one of the marking engines (e.g., the higher speed marking engine) sits idle while waiting for pages to be processed and delivered to the print buffer by the other marking engine (e.g., the lower speed marking engine).